U.S. patent number 6,884,337 [Application Number 10/151,610] was granted by the patent office on 2005-04-26 for production of basic hydrogen peroxide for chemical oxygen-iodine laser devices.
This patent grant is currently assigned to The Boeing Company. Invention is credited to Peter D. Amdisen, Thomas L. Bunn, Alan Z. Ullman.
United States Patent |
6,884,337 |
Amdisen , et al. |
April 26, 2005 |
Production of basic hydrogen peroxide for chemical oxygen-iodine
laser devices
Abstract
A method of generating basic hydrogen peroxide (BHP) fuel for a
chemical oxygen-iodine laser (COIL) using stored alkali chloride,
typically potassium chloride, and water. The alkali chloride and
water are mixed to form a saturated or nearly saturated aqueous
salt solution for use as an anolyte feed to a chlor-alkali cell.
The chlor-alkali cell generates alkali hydroxide, hydrogen, and
chlorine. Water and oxygen are reacted to form peroxide which is
combined with the alkali hydroxide from the chlor-alkali cell to
form a dilute solution of BHP, a mixture of hydrogen peroxide and
alkali hydroxide, which dissociates into O.sub.2 H.sup.- and .sup.-
OH. The BHP is concentrated and the molar ratio of hydrogen
peroxide to alkali hydroxide is adjusted to 1:1 before the BHP is
supplied to a COIL apparatus as fuel for the lasing process.
Inventors: |
Amdisen; Peter D. (West Hills,
CA), Bunn; Thomas L. (Simi Valley, CA), Ullman; Alan
Z. (Northridge, CA) |
Assignee: |
The Boeing Company (Seattle,
WA)
|
Family
ID: |
29419473 |
Appl.
No.: |
10/151,610 |
Filed: |
May 20, 2002 |
Current U.S.
Class: |
205/466; 205/516;
205/536; 205/620; 423/584 |
Current CPC
Class: |
C01B
7/01 (20130101); C01B 15/01 (20130101); C25B
1/30 (20130101) |
Current International
Class: |
C01B
7/01 (20060101); C01B 7/00 (20060101); C01B
15/01 (20060101); C01B 15/00 (20060101); C25B
1/00 (20060101); C25B 1/30 (20060101); C25B
001/30 () |
Field of
Search: |
;205/466,516,536,620
;423/584 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Phasge; Arun S.
Attorney, Agent or Firm: Alston & Bird LLP
Claims
What is claimed is:
1. A process for preparing basic hydrogen peroxide (BHP)
comprising: supplying alkali chloride and water from storage as an
aqueous solution to a chlor-alkali cell; introducing said aqueous
alkali chloride solution into the chlor-alkali cell, thereby
producing a liquid aqueous alkali hydroxide product stream, a
hydrogen gas stream, and a chlorine gas stream, supplying an oxygen
containing gas, reacting the oxygen in said oxygen containing gas
with water from storage in the presence of at least a first portion
of the alkali hydroxide product stream to produce a BHP solution
stream containing H.sub.2 O.sub.2 and dissociation products
thereof, alkali hydroxide and dissociation products thereof, and
water.
2. The method of claim 1, wherein the alkali chloride is selected
from lithium chloride, sodium chloride, and potassium chloride.
3. The method of claim 1, further comprising the step of mixing at
least a second portion of the alkali hydroxide product stream with
the BHP solution stream.
4. The method of claim 1, further comprising: reacting hydrogen
from a first portion of the hydrogen gas stream with chlorine from
a portion of the chlorine gas stream to form an HCl product stream,
and neutralizing basic components of the BHP solution stream with
the HCl product stream.
5. The method of claim 4, wherein the step of neutralizing the
basic components within the BHP produces alkali chloride and
wherein said method further comprises: chilling the neutralized BHP
stream, and separating alkali chloride and water from the chilled
neutralized BHP stream.
6. The process of claim 5, further comprising: feeding the chilled
and neutralized BHP stream from the alkali chloride separation step
to a COIL apparatus, recovering alkali chloride and water from the
spent BHP stream leaving the COIL apparatus, and recycling the
recovered alkali chloride and water to the chlor-alkali cell.
7. The process of claim 5, further comprising recycling at least a
portion of the water and alkali chloride from the chilled and
neutralized BHP stream to the chlor-alkali cell.
8. The process of claim 5, further comprising recycling at least a
portion of the water and at least a portion of the alkali chloride
from the chilled and neutralized BHP stream to the supply of stored
water and alkali chloride, respectively.
9. The process of claim 1, further comprising the step of reacting
hydrogen from a second portion of the hydrogen gas stream with
oxygen from the oxygen containing gas to form a water stream.
10. The process of claim 9, wherein at least a portion of the water
stream is recycled to the chlor-alkali reactor.
11. The process of claim 1, wherein the oxygen is supplied from an
air-oxygen enrichment apparatus.
12. A process for preparing basic hydrogen peroxide (BHP)
comprising: storing a supply of alkali chloride, storing a supply
of H.sub.2 O, supplying alkali chloride and H.sub.2 O from storage
as an aqueous solution to a chlor-alkali cell, feeding said aqueous
alkali chloride solution into the chlor-alkali cell to produce
alkali hydroxide and chlorine, supplying oxygen, feeding the water,
the oxygen, and the alkali hydroxide into a peroxide generator to
produce BHP, producing HCl from at least a portion of the chlorine
produced by the chloro-alkali cell, and supplying the BHP as fuel
to a COIL apparatus.
Description
FIELD OF THE INVENTION
The invention relates to a method for production of basic hydrogen
peroxide (BHP) for use in a Chemical Oxygen-Iodine Laser (COIL).
More specifically, the invention relates to a method of
manufacturing BHP without the need for hazardous handling,
transportation, or storage of hydrogen peroxide and alkali
hydroxide.
BACKGROUND OF THE INVENTION
The chemical oxygen-iodine laser (COIL) is a short wavelength
high-power chemical laser with wide ranging industrial,
technological, and military applications. The COIL produces a laser
beam with a 1.315-.mu.m wavelength, which is well suited to a
variety of uses. The COIL also has one of the best beam qualities
of any available laser, which allows for clean cuts and welds, as
well as simple beam correction and direction.
COILs are powered by solutions of basic hydrogen peroxide (BHP).
BHP is generated by the combination of alkali hydroxide, including
lithium, sodium, and potassium hydroxide, with hydrogen peroxide
according to the equation:
where M.sup.+ is any of the Li.sup.+, Na.sup.+ or K.sup.+ ions, or
other suitable ions, or mixture of these ions. The term BHP
typically refers to a solution having 4 molar to 8 molar
concentration of perhydroxyl ion (O.sub.2 H.sup.-), which is formed
by the reaction:
The perhydroxyl anions and alkali cations of the aqueous BHP
solution are then reacted with chlorine gas according to the
equation:
The resultant singlet delta oxygen (O.sub.2 (.sup.1.DELTA.)) is an
excited state of oxygen. Water vapor may be removed from the
products of reaction (III) and the products are accelerated to
supersonic velocity in an expansion nozzle to create a laser gain
region. Molecular iodine is injected and mixed with the gas flow.
The singlet delta oxygen has a resonance frequency very close to
the resonance frequency of atomic iodine and, when intermingled,
the singlet delta oxygen causes the rapid dissociation of the
diatomic iodine molecule and the excitation of the iodine atoms.
Energy is released in the form of light, which is extracted from
the excited iodine atoms by a laser resonator positioned transverse
to the direction of gas flow. The exhaust gases are usually removed
and scrubbed to remove residual chlorine and iodine. The BHP is
recycled until approximately 50-mol % of the perhydroxyl anions
have been used.
In order to generate the high-power laser required for industrial
and military applications, a COIL requires large initial volumes of
alkali hydroxides and hydrogen peroxide. The need to transport and
store large volumes of these materials presents a large hazard,
especially in the industrial and military environments in which
they will be used. Concentrated alkali hydroxides are extremely
corrosive. Concentrated hydrogen peroxide is also a logistical
problem. H.sub.2 O.sub.2 is extremely reactive and subject to
autocatalytic decomposition as well as rapid decomposition upon
exposure to a variety of trace impurities. The decomposition may be
accelerated by exposure to agitation, exposure to rough surfaces,
or exposure to metals.
Several prior art references teach methods of recycling BHP after
use so that fresh supplies of H.sub.2 O.sub.2 need not be supplied
during operation of a COIL, but there still remains the problems
presented by transportation and storage of the large initial
volumes of H.sub.2 O.sub.2 and MOH required for operation of the
COIL device.
What is needed is a method of supplying large quantities of BHP,
on-site, to a COIL device without the hazardous transportation and
long-term storage of peroxide and caustic alkali hydroxide
materials.
SUMMARY OF THE INVENTION
The invention is a method of generating basic hydrogen peroxide
(BHP) fuel for a chemical oxygen-iodine laser (COIL) using
relatively inert starting materials, i.e. an alkali chloride salt
and water. The invented method eliminates the need to store large
quantities of hydrogen peroxide and alkali hydroxides on site, thus
eliminating the need for monitoring systems and protective
equipment, and lowering the likelihood of mishap with highly
reactive hydrogen peroxide and caustic. As a further benefit of the
invention, the same process also produces the chlorine, or other
halogen, required for reaction with BHP in accordance with reaction
(III) above.
In general, the invented method begins with the storage of alkali
chloride, such as potassium chloride, and water. The alkali
chloride may be stored as a dried solid or as a saturated or
supersaturated aqueous solution. Of course, if a water source of
adequate cleanliness is readily available, then large amounts of
water need not be stored.
The alkali chloride and water is mixed to form a saturated or
nearly saturated aqueous brine solution for use as an anolyte feed
to a base production apparatus such as a membrane-type chlor-alkali
cell. The electrolytic operation of a chlor-alkali cell uses the
anolyte feed to generate a stream of alkali hydroxide, a gaseous
stream of hydrogen, and a gaseous stream of chlorine.
The alkali hydroxide from the chlor-alkali cell, together with
oxygen from air, an air enrichment apparatus, or a supply of stored
oxygen are fed to a peroxide production apparatus ("peroxide cell")
such as a membrane-type electrolytic cell to produce hydrogen
peroxide. There are a variety of methods for generating hydrogen
peroxide in aqueous KOH solutions, including electrolytic,
catalytic, and organic reaction schemes. The gaseous stream of
hydrogen from the chlor-alkali cell may also be used as a reactant
in the formation of hydrogen peroxide, depending on the chosen
reaction scheme.
The output of a typical peroxide generator, such as a membrane-type
electrolytic cell, is a combination of hydrogen peroxide and alkali
chloride with a molar ratio of approximately 1:2 (H.sub.2 O.sub.2
:MOH). A COIL apparatus generally requires BHP having a ratio of
approximately 1:1 (H.sub.2 O.sub.2 :MOH). In order to obtain a
molar ratio of 1:1, an acid, typically HCl, may be added to the BHP
leaving the peroxide generator prior to use in a COIL apparatus in
order to neutralize a portion of the alkali hydroxide. The acid may
be generated by reacting portions of the chlorine stream and
hydrogen stream from the chlor-alkali cell to form HCl.
Alternatively, the H.sub.2 O.sub.2 :MOH molar ratio of 1:1 can be
realized by employing an alkaline peroxide electrolytic cell with
an acid anolyte of the peroxide cell. In this embodiment, the MOH
formed in the chlor-alkali cell and oxygen, or air, flows to the
alkaline peroxide cell and H.sub.2 O.sub.2 and MOH are produced in
a 1:1 ratio. Other methods of producing H.sub.2 O.sub.2 may also be
used, such as catalytic or organic reactions.
Alkali chloride and water products resulting from the
neutralization step must be removed from the BHP solution prior to
use in a COIL. To remove the alkali chloride and water, the BHP
stream is chilled and the salt and water are separated from the
BHP. Both the alkali chloride and the water so collected may be
recycled to the chlor-alkali cell.
Thus, the invention provides a method of producing basic hydrogen
peroxide (BHP) which is substantially free of alkali chloride and
water and which has H.sub.2 O.sub.2 and alkali hydroxide components
in the proper molar relationship for use in a COIL apparatus. The
method provides the BHP from alkali chloride, water, and a source
of oxygen without the need to store or transport the relatively
hazardous hydrogen peroxide and alkali hydroxide reactants
previously used to generate BHP.
BRIEF DESCRIPTION OF THE DRAWINGS
Having thus described the invention in general terms, reference
will now be made to the accompanying drawings, which are not
necessarily drawn to scale, and wherein:
FIG. 1 is a block diagram of an embodiment of the invented chemical
system; and
FIG. 2 is a block diagram of an embodiment of the process of this
invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention now will be described more fully hereinafter
with reference to the accompanying drawings, in which preferred
embodiments of the invention are shown. This invention may,
however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein; rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. Like numbers refer to like
elements throughout.
In accordance with this invention, the alkali hydroxide and
hydrogen peroxide needed for the production of BHP are produced on
site from water, alkali chloride salt, and oxygen. The alkali
chloride material may be easily stored, and the necessary water or
oxygen may be either stored or readily obtained from commonly
available sources. Through a series of reactions, alkali hydroxide
and hydrogen peroxide are produced and concentrated to form BHP in
quantities and in proper molar ratios sufficient to power a COIL
device. As a further benefit, chlorine, or other halogens, required
for operation of the COIL device are also produced.
Reactant potassium hydroxide (KOH) and byproduct potassium chloride
(KCl) are typically used as the alkali hydroxide and alkali halide
components in the operation of COIL devices. Therefore, KOH and KCl
are used throughout this description as exemplary alkali hydroxide
and alkali halide compositions for use with the invention. Though
KOH and KCl are used as exemplary alkyl hydroxide and chloride, it
is noted that analogous reactions and compositions may be obtained
with other alkali hydroxides and halides as known in the art and
statements with regard to potassium hydroxide or chloride are
generally applicable to alkali hydroxides and chlorides. For
instance, U.S. Pat. No. 6,010,640 presents a method of using LiOH
rather than KOH as the alkali hydroxide for use with a COIL
device.
As used herein, BHP means any chemical solution having appreciable
amounts of the dissociation components of alkali hydroxide and
hydrogen peroxide, i.e. O.sub.2 H.sup.- and K.sup.+ when potassium
is the alkali component, wherein the primary active species is the
perhydroxyl ion (O.sub.2 H.sup.-). BHP for use in a COIL device is
preferably a mixture of KOH and H.sub.2 O.sub.2 having a molar
relationship of approximately 1:1 (KOH:H.sub.2 O.sub.2). In an
aqueous solution, the KHO and H.sub.2 O.sub.2 of the BHP form the
perhydroxyl ion through the following acid-base reaction:
COIL devices are most favorably operated, and the resultant BHP of
the overall invented process is preferably carried out at BHP
solution concentrations between about 4 moles O.sub.2 H.sup.- /L
and 8 moles O.sub.2 H.sup.- /L.
Referring to FIG. 1, which shows an embodiment of the invention,
alkali halide salt 11 and water 12 are stored on-site, ready for
use in the generation of BHP fuel. Water may be stored on-site in a
container such as a tank, or may be drawn from a natural or
municipal source. The salt is also stored in a container such as a
tank. The salt and water are mixed to form an aqueous salt solution
3. It is preferred that the salt solution 3, for example KCl
solution, be a saturated or nearly saturated solution. Potassium
chloride is the preferred alkali halide because it is a readily
available, naturally occurring compound which is soluble in water
in the amount of about 1 gram per 2.8 ml at standard temperature,
and has a pH of about 7. In general, the alkali halide salts are
inert and stable, and may be stored safely for indefinite
periods.
The aqueous salt solution 3 is fed as an anolyte material to a base
production unit 21, such as a chlor-alkali cell. When a
chlor-alkali cell is used as the base production unit 21, the cell
21 acts in fundamentally the same manner as the sodium chloride
chlor-alkali cells used in caustic soda production, such as those
discussed in U.S. Pat. No. 4,459,188. In operation, the anolyte
salt solution is contained within an anode chamber of the
chlor-alkali cell. By application of an electric charge to the
aqueous salt solution, chloride ions are oxidized at the anodes of
the chlor-alkali cell to chlorine. Alkali metal ions are
transported through an ion exchange membrane, into a cathode
chamber of the chlor-alkali cell. In the cathode chamber, the water
is reduced at the cathodes of the cell to form hydroxide anions in
aqueous solution. The overall reaction provided by the chlor-alkali
cell 21 is:
where the KCl and H.sub.2 O are fed to the chlor-alkali cell 21 as
a saturated, aqueous alkali chloride salt solution via inlet stream
3. The main product stream of KOH is released from the cell via
outlet stream 4. The hydrogen product is released from the cell via
a hydrogen gas outlet stream 6, and the chlorine product is
released from the cell via a chlorine gas outlet stream 8. In
general, therefore, the outputs of the base production unit 21 are
a caustic solution 4, chlorine gas 8, and hydrogen gas 6.
Water flow from the water source 12 to the chlor-alkali cell 21 is
controlled so as to maintain the appropriate concentration of the
KCl solution 3 entering the chlor-alkali cell 21. The KCl is
preferably a saturated brine solution, which has minimal solids
suspended within the solution which might interfere with the ion
exchange membrane of the cell. Water may be added to the KCl
solution 3 from water stored within the system, water taken from a
natural reservoir or municipal water supply, or water generated
with oxygen by combination of a portion of the O.sub.2 from an
oxygen enrichment apparatus 72 with a portion of the H.sub.2 from
reaction (IV) of the chlor-alkali cell 21.
At least a portion of the caustic solution 4 is used as an input to
a hydrogen peroxide generator 73. Oxygen 94 and water 12 are also
inputs to the peroxide production unit 73. This invention is
described in terms of peroxide generator that employs a base (i.e.
KOH), but would be applicable to a peroxide generator that employs
an acid (i.e. H.sub.2 SO.sub.4) anolyte also. The water is provided
from the stored water or water source 12 and oxygen is provided
from a storage unit, from the air, or from an oxygen enrichment
apparatus 72.
The hydrogen peroxide generator 73 is a reactor, which produces
hydrogen peroxide by one of several methods, including catalytic,
organic, or electrochemical methods. An exemplary method of
catalytic peroxide production is given in U.S. Pat. Nos. 5,972,305
and 5,976,486, an exemplary method of organic peroxide production
is the commercially known Anthraquinone method and the method shown
in U.S. Pat. No. 5,902,559, and exemplary methods of
electrochemical peroxide production are given in U.S. Pat. Nos.
4,357,217; 4,384,931; 4,430,176; 5,565,073; 5,647,968; and
6,159,349.
It is preferred that hydrogen peroxide be generated with an
electrolytic hydrogen peroxide generator 73. A particularly
preferred method of electrolytic generation of hydrogen peroxide is
found in the Journal of Applied Electrochemistry 25 (1995) pages
613-627 by PC Foller entitled, "Processes for the production of
mixtures of caustic soda and hydrogen peroxide via the reduction of
oxygen". By using the electrolytic cell synthesis, no supplemental
catalysts or organic solvents need to be maintained or supplied on
site. Further, it is likely that electric current will be available
when practicing this invention, either through a municipal power
supply or from a portable generator.
In one embodiment of the invention, the peroxide generator forms
hydrogen peroxide electrolytically from water and oxygen according
to the overall reaction:
According to the reaction of (V) in an electrochemical cell,
OH.sup.- is oxidized at the anode of the cell according to the
equation 2KOH.fwdarw.K.sup.+ +2e.sup.- +1/2O.sub.2 +H.sub.2 O. At
the cathode, oxygen is reduced according to the equation
O2+H2O+2e-.fwdarw.OH--+O2H--. Potassium ions, K+, are transported
across the cation exchange membrane, thereby carrying the current
and balancing the charge of the OH-- and O.sub.2 H-- anions in the
cathode.
Oxygen is preferably supplied 94 to the hydrogen peroxide generator
73, at or near the time of BHP production, from an air enrichment
apparatus 72 which removes oxygen from the air, such as a model
OG-5000 oxygen generator manufactured by Oxygen Generating Systems,
Inc. of Niagara Falls, N.Y. Alternatively, the oxygen required for
the hydrogen peroxide production may be supplied in gas cylinders
or generated by chemical reaction on site.
The KOH necessary for hydrogen peroxide production within the
hydrogen peroxide generator 73 is preferably supplied from the main
KOH stream 4 of the chlor-alkali cell 21. Depending on the chosen
method of H.sub.2 O.sub.2 production, KOH may or may not be
involved in the reaction to produce peroxide. In either peroxide
generator 73, KOH is not consumed by the reaction. Rather using the
preferred reaction of (V), a supply of an aqueous solution of about
20 wt % KOH feeds the H.sub.2 O.sub.2 generator to result in a
product solution containing a 1:1 molar ratio of KOH:H.sub.2
O.sub.2.
The output of the peroxide production unit 73 is a dilute solution
of basic hydrogen peroxide 82 (BHP) that may or may not be produced
in the desired molar ratio of 1 mole KOH to 1 mole H.sub.2 O.sub.2.
The dilute BBP goes through a product composition control unit 71
to balance the molar ratio of caustic and peroxide and to
concentrate the solution bringing the molar concentration of the
perhydroxyl anion up to 8M. All or a portion of the chlorine 8 and
hydrogen 6 produced in the base production unit 21 is also used in
the product composition control unit 71 to obtain the proper 1:1
molar ratio of KOH:H.sub.2 O.sub.2 within the BHP stream 88. As
part of the BHP concentration process within the composition
control unit 71, water and salt are removed from the BHP. The
removed water 90 and salt 92 is optionally recycled back to the
water supply 12 and salt supply 11, respectively. Excess water
removed in this unit may be reused in the base production unit 21
or peroxide production unit 73, or disposed.
Referring to FIG. 2, a preferred product composition control unit
71 is shown having an oxygen reactor 74, a chlorine reactor 75, a
base neutralizing unit 76, and a prechiller/separator 77. The
hydrogen peroxide stream 82 leaving the hydrogen peroxide reactor
73 is base-rich, with a nominal molar ratio of 2:1 (KOH:H.sub.2
O.sub.2). The base-rich BKP stream may also contain residual
amounts of KCl, which are preferably removed before the BHP
composition is used to fuel a COIL device.
For use in a COIL device, the molar ratio of KOH to H.sub.2 O.sub.2
should be approximately 1:1. In this embodiment, acid (HCl) is
preferably added to the BHP solution leaving the peroxide
generator, which is nominally 2:1 KOH:H.sub.2 O.sub.2 in order to
neutralize it before it is concentrated and used in the COIL
apparatus. To this end, streams of hydrogen 6 and chlorine 8 gases,
evolved from the chlor-alkali cell 21, are combined in a chlorine
reactor 75 to form hydrochloric acid according to the reaction:
This reaction typically occurs in the presence of UV light or on
the surface of a catalyst. The production of HCl from H.sub.2 and
Cl.sub.2 is well known in the art.
Production of HCl does not use all Cl.sub.2 generated by the
chlor-alkali cell, and excess Cl.sub.2 from the chlor-alkali cell
21 is either stored for later use or fed 13 to the COIL laser when
it is ready to be fired.
A stream of HCl 84 from the chloride reactor 75 is then reacted
with the base-rich peroxide/BHP stream 82 in a base neutralizing
reactor 76. A portion of the KOH from the base-rich BHP mixture is
reacted with the HCl to form potassium chloride and water according
to the following acid-base reaction:
HCl is added to the solution until the molar ratio of KOH to
H.sub.2 O.sub.2 approximates 1:1. At this point, the BHP stream is
composed primarily of BHP (O.sub.2 H.sup.-, H.sub.2 O, and
K.sup.+), water, and KCl in an aqueous solution.
Because the KCl may precipitate in a BHP solution and harm or
interfere with the operation of the COIL apparatus as the BHP is
cooled and pumped through the COIL device, most of the KCl must be
removed from the BHP stream. The BHP stream 86 from the base
neutralizer 76 is chilled to a low temperature, typically about
-20.degree. C., for removal of salt in a prechiller/separator
apparatus 77 to remove the salt. Most of the KCl is filtered and
removed from the BHP solution. Also, excess water is preferably
removed from the BHP solution. Water may be removed by vacuum
evaporation or other methods such as simply freezing the water out
of solution in the prechiller/separator 77. After water and salt
are removed from the BHP and after the molar ratio of KOH:H.sub.2
O.sub.2 is adjusted to 1:1, the concentration of the BHP will be in
the desired range of between 4 moles O.sub.2 H.sup.- /L and 8 moles
O.sub.2 H.sup.- /L. The resulting molar balanced and filtered BHP
solution 88 which has a proper molar balance of KOH and H.sub.2
O.sub.2 and has been filtered for removal of KCl and/or water is
stored or fed 88 directly to a COIL apparatus.
Neither the KCl 92, which is removed from the BHP solution, or the
water 90, which is also removed from the solution, are
environmentally hazardous and may be easily reused or disposed.
Preferably, the KCl 92 and water 90 are recycled back to the main
feed of the chlor-alkali cell 21, or alternatively the KCl 92 and
water 90 may be stored 11, 12 for later use. In this manner, both
KCl and water are conserved by the invented process. In this
preferred embodiment, KCl and water are continually recycled back
to the chlor-alkali 21 feed, so only oxygen 94 and energy are
required for the continual generation of BHP. Of course, it is not
necessary to the invention that the KCl 92 or water 90 be
recycled.
If an acid anolyte peroxide cell is used in place of the base
anolyte cell, then it may be that the BHP is produced with a
KOH:H.sub.2 O.sub.2 molar ratio of less than 1. In this case a
portion of the caustic stream 14 leaving the chlor-alkali cell 21
is combined with the BHP stream 82 leaving the peroxide generator
73 in addition to being fed to the peroxide generator 73.
Spent fuel from a COIL apparatus contains amounts of KCl and water,
which may be removed from the spent fuel. The KCl and water from
the spent BHP may be recycled back to the KCl or water storage
areas 11,12 or fed directly back to the chlor-alkali cell 21 for
regeneration of the BHP.
By using the invented method, stable, environmentally acceptable
and non-hazardous components, such as water and alkali chloride
materials, may be used to generate fuel for a COIL laser system.
The invention eliminates the need to store and transport dangerous
materials, such as hydrogen peroxide, potassium hydroxide, and
chlorine gas required for operation of a COIL system.
Many modifications and other embodiments of the invention will come
to mind to one skilled in the art to which this invention pertains
having the benefit of the teachings presented in the foregoing
descriptions and the associated drawings. Therefore, it is to be
understood that the invention is not to be limited to the specific
embodiments disclosed and that modifications and other embodiments
are intended to be included within the scope of the appended
claims. Although specific terms are employed herein, they are used
in a generic and descriptive sense only and not for purposes of
limitation.
* * * * *